5610611 REAL-WORLD EVIDENCE CHARACTERIZING THE BURDEN OF DISEASE IN ALPHA AND BETA THALASSEMIA PATIENTS IN THE USA: AN INTERIM ANALYSIS
Authors: K.M. Musallam, A.T. Taher, L. Lombard, K. Gilroy, K. Lewis, J. Mellor, K. Golden, M.D. Cappellini
Journal: HemaSphere (2023)

Introduction: Thalassemia is a rare disease caused by impaired red blood cell synthesis of α and/or β globin chains, resulting in ineffective erythropoiesis and chronic hemolytic anemia that may require transfusion therapy. There is a lack of real-world data describing disease burden in thalassemia patients, particularly those with non-transfusion-dependent (NTD) thalassemia and α-thalassemia. This analysis aimed to characterize the burden of disease in patients with thalassemia in the USA. Methods: Data were collected via the Adelphi Thalassemia Disease Specific Programme™, a point-in-time survey of thalassemia-treating physicians and their patients in the USA. Data collection started June 2022 and is ongoing, with data presented here from an interim analysis as of 24th August 2022. Physicians completed a structured online survey for the consecutive patients with α-thalassemia (α-thal) or β-thalassemia (β-thal) seen during the study period. Ethics exemption was obtained from Pearl Institutional Review Board. Results: A total of 28 hematologists/hematologist-oncologists completed surveys for 127 patients, 55 (43%) with α-thal and 72 (57%) with β-thal. Mean patient age was 36.5 and 31.0 years for α-thal and β-thal, and 29 (53%) and 41 (57%) patients were male, respectively. Forty-three (78%) patients with α-thal were trait/carrier (Table 1), and β-thal intermedia (36 [50%]) was the most common type of β-thal. The most frequently physician-reported thalassemia-related symptoms/complications experienced by patients with α-thal and β- thal at the time of data collection were fatigue (28/49 [57%] and 31/60 [52%%], respectively) and anemia (24/49 [49%] and 32/60 [53%], respectively). Seven (13%) patients with α-thal and 10 (14%) with β-thal were considered transfusion dependent (TD) by their physicians while the remaining patients were considered NTD. The most common reason for being considered TD was high risk of patient mortality without transfusions (3/7 [43%]) for α-thal and patient requires multiple transfusions a year due to low blood counts/low hemoglobin (8/10[80%]] for β-thal. Where known, in the 12 months prior to data collection, patients with physician-defined TD α-thal and β-thal received a median of 2.0 (range: 2-12) and 5.0 (range: 2-10) blood transfusions, whilst patients with physician-defined NTD α-thal and β-thal received a median of 0.0 (range: 0-3) and 1.0 (range: 0-3) blood transfusions respectively. Where known, physicians reported that patients with TD α-thal (n=7) and β-thal (n=9) had an average pre-transfusion mean hemoglobin of 10.9 g/dL and 8.4 g/dL and NTD α-thal (n=42) and β- thal (n=59) had a mean hemoglobin of 10.2 g/dL and 9.6 g/dL, respectively. Iron overload due to transfusions was reported in 5/41 (12%) of α-thal and 14/61 (23%) of β-thal patients. Iron chelation was prescribed in 34 (27%) of patients, luspatercept in 23 (18%) and hydroxyurea in 20 (16%). The most frequently reported issues/unmet need for iron chelation was ‘treatment does not reduce the severity of symptoms’ (9/34 [26%]), for luspatercept was ‘patient has to take time off work’ (7/23 [30%]), and for hydroxyurea ‘treatment does not reduce patient’s fatigue’ (7/20 [35%]) patients (Table 2). Conclusion: Despite currently available treatment approaches, both α- and β-thalassemia patients still experience substantial disease burden. Effective and convenient treatment approaches that target fatigue and improve Hb remain an unmet need for many patients.